The diagnostic yield of capsule endoscopy can be limited by the presence of dark or opaque intestinal contents. This can hamper or prevent diagnosis by causing incomplete visualization of the intestinal mucosa. In addition, slow gastric emptying or small bowel transit can prevent the capsule from reaching the ileo–cecal valve within the battery life. For these reasons, several studies have examined the possibility of improving bowel cleanliness and shortening transit time by means of medications and postural tricks. These studies, however, are heterogeneous in design and results. For these reasons, the best type and dosage of medications remain to be established with appropriately designed studies.